I been making caps for a about 6 months.
The easiest method is to forgot matching batches. Just mix all the primal bags in a plastic container.
Then make a cap holder out of a piece of an 4mm acrylic sheet. This should place the empty caps at just below or at the surface level of the acrylic sheet.
Dust the the sheet with primal and then use a fine bristled brush to spread the primal into all the caps. Brush excess back into container. Now take a match stick and compress the priming compound.
Move acrylic holder to a new dry clean area. Move caps to new location. Brush any remaining priming compound back into container.
Now using a spray bottle mist the caps generously with denatured alcohol. Let dry for 24 hours. Then spray with a cheap hair spray, again being generous. These last two steps set the compound and seal the compound into the caps.
A little bit overcharged. However, I have yet to have a hang fire using caps with this method.